1. Field of the Invention
The present invention relates to a connector, a terminal fitting and a disengagement jig.
2. Description of the Related Art
Japanese Unexamined Patent Publication No. 6-325814 and FIG. 28 herein disclose a connector with a housing 1 and terminal fittings 2. The housing 1 is formed with cavities 3, and the terminal fittings 2 are insertable into the cavities 3 from behind. A deformation permitting space 4 is formed adjacent each cavity 3 and a resin lock 5 is formed between the cavity 3 and the deformation permitting space 4. The lock 5 deforms into the deformation permitting space 4 in response to pushing forces exerted by the terminal fitting 2. However, the lock 5 is restored resiliently to engage the terminal fitting 2 when the terminal fitting 2 reaches a proper depth. Each lock 5 has an arm 6 that is cantilevered forward from the upper wall of the cavity 3 and a locking projection 7 that projects into the cavity 3 from the inner surface of the leading end of the arm 6 to engage the terminal fitting 2. Each cavity 3 has a front wall 8 with a tab insertion hole 9 for insertion of a mating tab terminal into the cavity. A mold-removal hole 5a is formed above the tab insertion hole 9, and is used to remove a mold pin for forming the locking projection 7 during the molding of the housing 1. A guide surface 9a is formed around the periphery of the tab insertion hole 9 for guiding the tab terminal into the tab insertion hole 9.
A demand exists to reduce the size of the above-described connector. Accordingly, the terminal fittings 2, the cavities 3 and the locks 5 are made smaller. However, the resin locks 5 are less rigid than the metal terminal fittings 2 and the locks 5 must have a minimum size to obtain a required force to lock the terminal fittings 2. Thus, if the cavities 3 and the terminal fittings 2 are made smaller while setting the size of the resin locks 5 at a specified fixed size, the projecting ends of the locking projections 7 of the locks 5 reach a height overlapping the guide surfaces 9a. Consequently, the mold-removal holes 5a for the locks 5 effectively reduce the areas of the guide surfaces 9a, and impede the ability to guide a misaligned tab into the tab insertion hole 9.
A disengagement jig can be inserted into the mold-removal hole 5a from the front and can be maneuvered to deform the lock 5 so that the terminal fitting 2 can be removed. However, the jig becomes narrower and weaker as the opening area of the mold-removal holes 5a becomes smaller.
Forces generated during a disengaging operation could deform of the resin lock 5 excessively. Thus, an excessive deformation-preventing wall 6 is provided on the side of the deformation space 4 opposite the resin lock 5. The excessive deformation-preventing wall 6 engages the resin lock 5 and prevents the resin lock 5 from deforming beyond its resiliency limit.
The resin lock 5, the deformation space 4 and the excessive deformation-preventing wall 6 are provided one over another along the height direction, and tend to make the connector very tall.
In view of the above, an object of the invention is to improve the operational efficiency of a connector.
The invention is relates to a connector with a housing that has at least one cavity. A terminal fitting is insertable into the cavity from behind and is electrically connectable with a mating tab terminal. The housing has a front wall with a tab insertion hole that permits entry of the tab terminal into the cavity. The front edge of the tab insertion hole has a guide surface for guiding the tab terminal into the tab insertion hole. A resiliently deflectable lock is at an inner surface of the cavity, and is engageable with the terminal fitting inserted into the cavity. Part of the lock overlaps the guide surface with respect to the height direction. A mold-removal hole penetrates the front wall of the cavity and cuts off a portion of the guide surface corresponding to the overlapping part as a mold for forming the lock is removed forward. The overlapping part of the lock is narrowed toward its upper side, and the mold-removal hole preferably is formed along the outer periphery of the narrowed portion.
Accordingly, it is possible to guide a tab terminal smoothly into a tab insertion hole. The terminal fitting inserted into the cavity is engaged by the lock and is held so as not to come out of the cavity. Thereafter, a mating tab terminal is inserted into the cavity from the front through the tab insertion hole and is connected electrically with the terminal fitting. A misaligned tab terminal slides along the guide surface and is guided smoothly into the cavity.
The narrowed portion of the lock that overlaps the guide surface enables the mold for forming the lock to have a narrow leading end. The mold-removal hole is at a part of the front wall of the cavity where the guide surface is formed and has a shape conforming to the outer periphery of the narrowed portion. Thus, an area of the guide surface cut off by the mold-removal hole can be made smaller as much as the narrowed portion is narrowed. Accordingly, the guide surface for the tab terminal is as large as possible, and the tab terminal can be guided smoothly into the tab insertion hole.
The narrowed portions preferably are at opposite sides of the lock, and the mold-removal hole preferably defines an M-shape. The widths of portions of the mold-removal hole that correspond to the narrowed portions can be made smaller by providing the narrowed portions at the opposite widthwise sides of the lock. Thus, the tab terminal can be guided more satisfactorily since the part of the guide surface interrupted by the mold-removal hole is divided into two portions, and the widths of the individual interrupted portions is small.
The bottoms of the opposite ends of the substantially M-shaped portion of the mold-removal hole and the end of a portion between the two narrowed portions are at substantially the same height.
Portions of the guide surface at a recessed midpoint of the M-shaped portion of the mold-removal hole and portions thereof at the opposite bottom ends of the M-shaped portion are substantially aligned.
A projection on the terminal fitting slides in contact with surfaces between the two narrowed portions to guide the terminal fitting into the cavity. Thus, widthwise shaking of the terminal fitting is suppressed.
The sliding-contact surfaces preferably are inclined inversely of each other and converge. Accordingly, the terminal fitting is guided to a widthwise center position to suppress the widthwise shaking, and the insertion of the terminal fitting is easier.
The lock preferably is engageable with a rear end of the projection.
The construction of the terminal fitting can be simplified by using the projection as the engaging portion that is engageable with the lock.
The leading end of the narrowed portion preferably reaches the tab insertion hole with respect to height direction, and the narrowed portion may be substantially at the widthwise center of the lock.
The narrowed portion of the lock may have a height that reaches both the guide surface and the tab insertion hole. Thus, the mold-removal hole communicates with the tab insertion hole. The narrowed portion may be substantially at the widthwise center of the lock, and the edge of the mold-removal hole along the outer periphery of the narrowed portion is more inward, thereby making the guide surface larger.
A portion of the lock that engages the terminal fitting preferably is more toward the base end of the lock than the narrowed portion(s).
When the terminal fitting is inserted into the cavity, the projection slides in contact with the sliding-contact surfaces between the narrowed portions of the lock. Thus, widthwise shaking of the terminal fitting is suppressed and the insertion operability of the terminal fitting is better.
A large shear area is more toward the base of the lock end than the narrowed portion. Thus, a force to lock the terminal fitting can be larger.
The lock preferably includes a resiliently deformable arm and a locking section that engages the terminal fitting inserted into the cavity and having the overlapping part. The arm is formed before the locking section and has a groove for receiving a projection on the terminal fitting. The projection inserted in the groove is engageable with the locking section.
The projection presses the locking section while the terminal fitting is being inserted into the cavity to deform the arm. The arm is restored resiliently when the terminal fitting is inserted to a proper depth, and the projection is inserted into the groove to be engaged by the locking section. In this way, the terminal fitting is held so as not to come out of the cavity.
The arm is formed with the groove and the projection inserted into the groove is engaged with the locking section. Thus, the distance between the leading end of the locking section with respect to height direction and the tab insertion hole can be made longer by the height of the groove while ensuring a sufficient engaged area of the locking section with the projection. Additionally the distance between the mold-removal hole and the tab insertion hole can be made longer, and a large area can be ensured for the guide surface with which the tab terminal is to be held in sliding contact. Therefore, the tab terminal can be guided more smoothly to the tab insertion hole.
The invention also relates to a terminal fitting for the above-described connector. The terminal fitting has a projection for sliding contact with the surfaces between the two narrowed portions to guide the terminal fitting into the cavity. The construction of the terminal fitting can be simplified by using the projection as the engaging portion engageable with the lock.
The invention also is directed to a disengagement jig to be used for the above-described connector for withdrawing the terminal fitting from the connector or the cavity. The jig comprises a shaft that is insertable into the mold-removal hole. The jig can act on and resiliently deform the lock. A reinforcing rib extends substantially along the longitudinal direction of the shaft and is insertable into the portion of the mold-removal hole corresponding to the narrowed portion. Thus, the jig is strong even if the shaft is narrowed to cope with the miniaturization of the connector.
The disengagement jig may have a restricting portion for engaging the housing and restricting an inserted depth of the disengagement jig into the mold-removal hole to a position reached before the disengagement jig interferes with the lock. Accordingly, the disengagement jig will not get stuck in the lock and damage can be avoided.
The disengagement jig is used in a connector with a terminal fitting that includes a resilient contact piece for contacting a tab terminal. An erroneous-insertion restricting portion restricts an inserted depth of the disengagement jig into the tab insertion hole to a position reached before the disengagement jig interferes with the resilient contact piece.
The restricting portion also is the erroneous-insertion restricting portion that restricts an inserted depth of the disengagement jig into the tab insertion hole to a position reached before the disengagement jig interferes with the resilient contact piece. Thus, the jig is simplified.
Excessive deformation preventing portions may be provided for engaging the locks and preventing the locks from being excessively deformed. An engaging surface of each lock with the corresponding excessive deformation-preventing portion is retracted from a leading end surface of the lock with respect to the deforming direction. Each excessive deformation-preventing portion overlaps a portion of the deformation space into which the lock deforms.
The excessive deformation preventing portions can be closer to the corresponding locks by as much as the engaging surfaces are retracted from the leading end surfaces. Thus, the connector can be made smaller by a corresponding amount.
An engageable surface of each excessive deformation-preventing portion is to be engaged with the engaging surface of the corresponding lock. Thus, a pushing force that acts on the excessive deformation-preventing portion when the engaging surface engages the engageable surface can be alleviated. This eliminates the need for a special consideration to enhance the strength of the excessive deformation preventing portions, thereby improving a degree of freedom in the connector designing.
The cavities preferably are at a plurality of stages along the deforming direction of the locks. The locks, the deformation spaces and the excessive deformation preventing portions are formed by cutting partition walls that partition the cavities that are adjacent along the deforming direction of the locks. The deformation spaces are formed to communicate with the cavities adjacent along the deforming direction of the locks, and each excessive deformation-preventing portion can prevent a loose movement of the terminal fitting by engaging the terminal fitting inserted into the adjacent cavity.
A connector may be miniaturized by forming the locks, the deformation spaces and the excessive deformation preventing portions by cutting the partition walls, and the adjacent cavities of such a connector may communicate with the deformation spaces. Each excessive deformation-preventing portion in such a connector is engageable with the terminal fitting inserted into the adjacent cavity, and the terminal fitting is prevented from making a loose movement to enter the deformation space.
The locks, the deformation spaces and the excessive deformation preventing portions preferably are formed by cutting an outer wall of the connector housing. Thus, the deformation spaces communicate with outside. Each excessive deformation-preventing portion can protect the corresponding lock by being provided to cover an outer surface of the locking portion.
The deformation spaces may communicate with the outside to expose the locks. However, the excessive deformation preventing portions substantially prevent external matter from interfering with the locks from the outside, thereby preventing the locks from being damaged.
These and other objects, features and advantages of the present invention will become more apparent upon reading of the following detailed description of preferred embodiments and accompanying drawings. It should be understood that even though embodiments are separately described, single features thereof may be combined to additional embodiments.